1. Field of the invention
The present invention relates to an image forming apparatus which comprises detachable process-units such as a photoconductor unit, a developing unit, and the like, each of which integrally contains components and consumable supplies associated with each other for performing each step of the image-forming process, so that the replacement of such components and consumable supplies can be performed simply by replacing the corresponding process-unit.
2. Description of the prior art
With the recent increase of personal use, image forming apparatuses such as electrostatic process copying machines have been developed which comprise process-units such as a photoconductor unit, a developing unit, etc., so that the components and consumable supplies contained therein can be replaced with ease at the user side, simply by replacing the process-unit.
FIG. 3 shows a typical image-forming apparatus of this type, wherein a photoconductive drum 11, a charger 12, and a cleaner 13 constitute a photoconductor unit 14, while a toner hopper 15 and a developer tank 16 make up a developing unit 17. The photoconductor unit 14 and the developing unit 17 are both supported on a rail 18. A door 19 provided on one side of the apparatus (i.e., on the right side in FIG. 3) can be opened to rest in a position indicated by the two-dot dash lines. The door 19 is opened when the developing unit 17 and the photoconductor unit 14 are to be removed for replacement.
Generally, image forming apparatuses for which components and consumable supplies can be replaced as process-units by the user are designed in compact size, making full and effective use of the machine's internal space and leaving hardly any idle space therein. This has in turn restricted the space for the replacement of the developing unit 17, the photoconductor unit 14, etc., thereby making it difficult for the user to replace them and giving rise to a possibility of damaging adjacent components during the replacement work. Such problems have been particularly easy to arise when replacing the photoconductor unit 14 which is installed in the middle part of the copying machine because it requires work deep inside the machine.